The Constitution premises Congress’s copyright power on promoting “the Progress of Science.” The word Science therefore seems to define the scope of copyrightable subject matter. Modern courts and commentators have subscribed to an originalist view of Science, teaching that Science meant general knowledge at the time of the Framing. Under this interpretation, all subject matter may be copyrighted because expression about any subject increases society’s store of general knowledge. Science, however, did not originally mean general knowledge. In this Article, I examine evidence surrounding the Copyright Clause and conclude that at the Framing of the Constitution, Science meant a system of knowledge that comprises distinct branches of study. This historically accurate meaning casts doubt on whether a distinct group of expression may be copyrighted — namely, expression that the First Amendment does not protect. I argue that the original meaning of Science cannot support a constitutional copyright of unprotected speech.